Kontaktallergien gegen ophthalmologische Lokaltherapeutika – eine epidemiologische Risikobewertung

BACKGROUND: Contact allergies (CA) against active agents of topical ophthalmological therapeutics, causing inflammation of the conjunctiva and/or the lid, are usually not life-threatening, but occur not infrequently. As yet, the assessment of the CA-eliciting risk has been based on clinical data alone, while a valid epidemiological risk assessment is lacking. MATERIALS AND METHODS: The Information Network of Departments of Dermatology supplied information on diagnostic results obtained in 4,102 patients patch-tested for suspected CA to ophthalmic drugs between 1995 and 2004. Clinical prevalences were extrapolated to incidences at the German population level. These estimates served as numerator for a relative incidence (RI), which included the nationwide frequency of prescriptions collected by the WIdO, Bonn, in terms of a standardised defined daily dose (DDD) as denominator. RESULTS: The estimated annual incidence of CA ranges from 155 (atropine sulphate) to 2077 (gentamicin sulphate) and can thus be regarded as moderate. If incidence estimates are related to prescription frequencies, the highest risk was found for kanamycin and neomycin sulphate (RI > 8 / 100,000 DDD). In contrast, the RI of pilocarpine-HCl (0.3) was virtually negligible. CONCLUSIONS: The substance-specific risk of CA has been evaluated for the first time and found to differ between therapeutics (with a similar spectrum of application). CA risk should be considered in differential therapeutic decision-making.